Generally, an LED (light emitting diode) chip with high brightness, long life, energy conservation and environment protection is widely used in lighting area and display area.
While the LED chip is used in display area, the LED chip is always used as a backlight module in a display device. Nowadays, with the development of the display device, a size of the display device is more and more smaller, so a smaller size of LED chip is also needed to used in the display device. However, because of a smaller size of the LED chip, while the LED chip is manufactured, a detection method for the LED chip to ensure a good quality of the LED chip is needed and difficult.